Lanterns episode 5, "Lights Out," brings us to the end of the show's 2016 timeline, and a lot happens before John Stewart makes a decision that changes everything.
We kick things off in 2007, the night Kerry, the daughter of a Gotham City gangster, arrives in Rushville. She's pursued by two men who reveal that because her father was a snitch, she's considered a snitch, too, meaning they have to kill her. Zoe intervenes, killing one of them and threatening the other (if he doesn't return to Gotham with Kerry's pinkie, his boss will just send more men).
Kerry cuts her finger off and pledges her allegiance to Zoe, who says she'll grow her a new finger in exchange for the Gothamite one day protecting her.
In 2016, John is trapped in the car that Hal left him in at the end of last week's episode. The Green Lantern tells his trainee that he'll pit Antaan against William Macon, so he can capture Zoe and take her to the Guardians of the Universe on Oa, where they'll be "lining up to kiss my ring."
Zoe, meanwhile, says goodbye to her grandson—warning the boy to remember everything she told him—before finding John and watching him burn alive, an unexpected consequence of Hal's actions that he surely can't have seen coming.
At the hospital, Zoe confirms that she killed Abin Sur because there was a risk that, even after saving her from the Guardians, he might one day change his mind and reveal where she is. Zoe heals John in exchange for his loyalty, while Hal breaks something off his ring to "Activate Sentry Protocol" and use the Halogram to help him find Zoe.
In a confrontation with Kerry, Hal learns that the Manhunter gave the Sheriff a "miracle." While she doesn't specify what that is, it's safe to assume it's her son. How much are we betting that he's also a Manhunter, and likely Hal's killer in 2026?
Hal fools Antaan into believing the Manhunter is William, who dies at the alien's hands. However, all hell breaks loose in town, with Zoe unleashing the full force of her satellites on innocents to deplete the charge in Hal's ring and kill him. John escapes the hospital and promises his parents that he'll take Hal's ring, though he's busy fighting Zoe's men and making short work of Antaan, who it turns out is not Atrocitus, after all.
Returning to the motel, Hal goes to charge his ring, but gets his ass handed to him by John. Zoe points one of her satellites at the room they're fighting in, prompting Hal to use the last of the ring's energy to put up a bubble that protects them from the blast. When the dust settles, Hal is under the rubble, and John is gone, allowing Zoe to approach Hal for the kill shot.
However, what she doesn't realise is that John is using Hal as bait. He shoots Zoe in the head, tears out her heart—which turns into crystal—and takes the ring before meeting with Lianna.
With Hal's words—"They replaced me... They'll replace you, too!"—ringing in his ears, John tells Lianna that he felt empty when he put the ring on. He watched Hal go against his oath and everything he stands for to keep it, and decides he no longer wants it. With that, he leaves it on the bar and leaves.
So, it's now safe to assume that, in 2016, the Guardians gave the ring to Guy Gardner, leaving John to return to a normal life (likely earning the scorn of his parents) and Hal to fade into obscurity. In the remaining three episodes, the spotlight will shift to figuring out who killed Hal and, somehow, getting a ring on John's finger.
Zoe's grandson being responsible for Hal's demise seems a given, and Lanterns has completed what many fans feel is a full-blown Hal Jordan character assassination. There's still time to redeem him, somehow, but as of now, it no longer feels like we should expect Parallax or some kind of misdirect that reveals he's alive and well.
Still, Hal initially abandoning innocents and essentially leaving John to die reeks of someone infected by fear, so perhaps we will see him break bad? That and an eventual redemption arc could save the character, but it may be wishful thinking.